A standard container for nuclear inventory has an end wall, a side wall, and a lid. The container forms a closed chamber for the radioactive inventory.
In such containers the connection of the container lid to the side wall forms under extreme circumstances a relative weak point because the connection is often reversible. For example, screws are understood as reversible connections. Since such the containers are characterized by a very long life, the containers have to be configured for a number of extreme situations. Herein included are, for example, extreme impact situations such as falls from a height of several meters. In the case of such falls, the potential energy of the container is converted into deformation energy, and, based on the solid construction of the container walls, the greatest force is exerted on the screws, in particular when the container lands in a so-called “lid flat fall” with the lid down, that is on its lid. If the yield point of the screws is exceeded, the screws are plastically deformed. In an extreme case, the plastic deformation can lead to a leakage of the container.
From practice is it further known to provide containers holding fuel elements with plastically deformable shock absorbers within the container. These shock absorbers are cylindrically tubular and made of aluminum. In the case of a fall through several meters on the horizontal lid, the fuel elements crash onto the hollow cylindrical shock absorbers, as a result of which the shock absorbers are plastically deformed in an accordion-like manner. This plastic deformation of the shock absorbers dissipates a considerable portion of the potential energy so that the stresses in the screws are reduced at least to the extent that no plastic deformations of the screws results. However, the hollow cylindrical shock absorbers from the prior art known from the practice are attached via further screws to the inner face of the lid. Consequently, threaded holes are required on the inner face of the lid, as a result of which the lid loses stability. Moreover, the manufacture of the hollow cylindrical shock absorbers as well as their attachment on the inner face of the lid require a certain effort. After all, the inventory in form of the fuel elements has to be guided to the shock absorbers by guide heads to ensure that the inventory does not slide past the shock absorbers and, in this way, crash in an uncushioned manner onto the lid.